


The demon king's heir

by Lunatical



Category: Iron Man - All Media Types, The Avengers (Marvel) - All Media Types
Genre: Alcohol Abuse/Alcoholism, Author Is Sleep Deprived, BAMF Tony Stark, Child Abuse, Demon AU, Demon Tony Stark, Gen, How Do I Tag, Howard Stark's A+ Parenting, I'm Sorry, Kidnapping, Magic, Team as Family, also so many bad puns about hell, bad choices, by making a deal with satan, howard tried to create a new supersoldier, i'm very tired, maybe i will expand this universe later on, this is kinda rushed
Language: English
Status: Completed
Published: 2016-10-27
Updated: 2016-10-27
Packaged: 2018-08-27 09:32:50
Rating: Not Rated
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 2,238
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/8396563
Author URL: https://archiveofourown.org/users/Lunatical/pseuds/Lunatical
Summary: AU where Tony Stark is the son of Satan, but he still finds himself with a great familyORthe one where Tony can't keep a secret to save his life, everyone cries a lot and too many things are set on fire.





	

When he was six, his mother sat him down with a serious expression on her face. It wasn’t unusual for her (being married to Howard Stark often made her unhappy), but she was usually smiling around him.

Maria let out a weary sigh and passed a hand through her hair, trying to find the best way to explain what she had to say to a child.

Eyes far too clever for such a small human were looking at her expectantly.

“Bambino mio, I need to tell you something. It’s a really important secret, and you need to make sure that nobody ever finds out. It might be really scary and you might not understand, but I need you to trust me, ok?”

She felt his gaze on her, his natural charm drawing her attention.

 _Yeah_ , she thought, _he will have to work on that a lot._

Tony was curios, even if a bit worried.

“Okay, mamma.”

With a last sigh, she started talking.

 

-

 

It wasn’t until ten years later that the first real “accident” happened.

Howard had been drinking again. They were all in his office, Tony listening in silence while his father tore him down and Maria tried and failed to calm him down.

“You’re just nothing but a disappointment.” The words were spat out like pure venom. “You’re the son of the most powerful creature in Hell and you can’t even create a decent weapon! You should have been the new Super Soldier thanks to magic in your veins, but all I get is this useless…”

Howard was cut off by a deep growl. Over his drunkenness, his brain registered the danger he was currently in, but he was way too inebriated to be able to completely understand the situation.

On the other side of the room, Tony was desperately trying to hold his emotions in check.

Anger, hurt, sadness… a swirl of feelings that he couldn’t process.

Then he heard it.

A deep, gravelly voice whispering in his ear.

 _Show him_ , the voice said, _show him what you really can do._

A flare of rage tore through his body.

Something was tingling on his forehead and back, but all he could focus on was the pure need for blood he was feeling. He embraced it, falling into it. He didn’t hear his mother screams. He could only hear the voice in his head, telling him to give in.

He did.

 

-

 

When he came back to himself, Maria was holding his face with tears streaming down her face, a litany of “Tony”s falling from her lips like a broken record. Howard was on the ground behind her, staring at him with terror in his eyes. Tony looked down to the burnt carpet around him. There were scorch marks on the walls and his father’s desk was reduced to a pile of ashes.

His mother brushed a strand of hair away from his eyes, and her hand bumped on something on his forehead.

With a frown, he tried to touch the object, only to take his hand away almost as if he had been burnt.

He had horns.

Well, shit.

 

-

 

He trained with Jarvis for the next two years. The butler had read everything available on demons and was teaching him how to control his powers.

After months of work, Tony could now fully control his transformation: horns, wings, teeth, claws, he had the whole package.

Dizzy with happiness and with a smirk on his face, he turned to the man that had been his father more than anyone else in his life.

“Hey, Jarvis.”

“Yes, Master Anthony?”

The words were spoken fondly, and Tony felt another wave of affection for the man. His smile went soft around the edges, and his eyes sparkled with joy.

“You know, you’re really one hell of a butler, J.”

The older man had to suppress a grin.

“I try my best, Sir.”

 

-

 

Jarvis was the one who called him and informed him of the car accident. He was the one who managed to calm him down. He was the one who held him when, after his parents’ death, Tony met his Father for the first time.

He never wants to see Hell again.

 

-

 

He makes friends, Pepper and Rhodey, and for the first time in years he feels like he can trust someone.

His mother’s words are still an echo in his mind _._

_Don’t tell anyone._

But he never really listened to his parents.

When he told them, Pepper informed him that she was going to throw holy water at him the next time he missed a meeting and then proceeded to hug him.

(They both cried. Tony will deny it if you ask.)

Rhodey only muttered something about knowing that “a troublemaker like you had to be the spawn of the Devil” and “why is my life like this”. After that he hugged him too, and they drank beer until Tony almost set fire to the couch. Pepper didn't find it as funny as they did.

(Rhodey now says “you make my life a living hell” every time something small and inconsequential happens. Tony has to suppress a laugh every time.)

Tony loved them both a little more after that.

 

-

 

See, the problem of living with someone who knows the truth is that you get used to being yourself in your home. Pepper didn’t get weird when she found him flying around his workshop in his “other form” and Rhodey didn’t mind having his best friend draped all over him during movie night, even though he was a small furnace.

(They did, however, scream at him when he tried to cook dinner by breathing fire. He also had to build a new kitchen, but that happened quite regularly even before.)

 

Then the Avengers showed up and messed up the whole thing.

He couldn’t teleport around anymore. He couldn’t fly without his armor. He had to constantly check himself to be sure he wasn’t doing anything weird.

It was getting annoying real fast.

Pepper and Rhodey told him to just tell them and be done with it, but he couldn’t bring himself to do it.

_Don’t tell anyone._

He still didn’t trust them.

 

-

Then they all got kidnapped.

-

 

Tony woke up to someone calling his name insistently. Groaning, he opened his eyes to find himself in a cell. A quick check of his surroundings showed that he was not alone, and that he was (together with his teammates) chained to a wall by his arms.

Looking at his team, that was staring at him in silence, he asked the obvious question for that situation.

“So, where are we?”

Natasha raised an unimpressed eyebrow, which, ok, that was in fact a stupid question, but he hadn’t had coffee yet and the silence was creeping him out.

It was Steve who answered, after another couple of seconds.

“We were kidnapped. The villain had a wide range stunning ray that apparently also works on gods and supersoldiers.”

 _And demons,_ Tony added in his head.

“We’ve been here for a couple of hours. They came in once to inject Bruce with something. We think it might be a sedative to keep the Big Guy out.”

Tony hummed in acknowledgement and stretched his legs.

“Anything from SHIELD?”

Clint shook his head.

“Comms are down. They took all of our weapons and got rid of the trackers. They’re not amateurs, that’s for sure.”

Tony nodded, checking his restraints. They weren’t reinforced. Good to know.

“Cap, I assume you tried to break the chain, right?”

Steve nodded, a grim expression on his face.

“Both mine and Thor’s are reinforced. We couldn’t break them.”

Looking at his teammates, Tony came to a decision.

“Ok, I need you to trust me. Please don’t freak out, and I’ll explain when we are back home.”

The avengers looked at each other with confusion, but he didn’t pay any mind to the dumbfounded expressions on the others’ faces, concentrating on the restraints.

Applying a little bit of his superhuman force, he was able to break the chains easily. He stood up, stretching his arms over his head and feeling his bones pop. With a satisfacted sigh, he strolled over to Clint and Natasha, breaking their shackles in a couple of seconds.

“Help me and get the others out. You are better at picking locks than I am.”

Also, if the chains could hold a god they could probably hold a half-demon.

The two spies nodded and went over to where Steve and Thor were gaping at Tony.

It was Clint who spoke first.

“So, Stark,” Clint glanced at Tony, who was examining the bars of their cell “when were you planning on letting us know about your super strength?”

Tony shrugged.

“It’s a bit more complicated than that. I wasn’t sure you weren’t going to freak out on me, so I thought it was better to wait.”

Clint scoffed.

“Dude, we’re on a team with a god, a man from the 1920s, a green radioactive monster and a guy in a suit of armor. Last week we all witnessed Natasha take down a purple alien with nothing but her thighs. You don’t really expect us to get weird because you’re what? A bit stronger than normal?”

His sentence was punctuated by the sound of two pieces of metal hitting the ground almost simultaneously, both the restraints opened by the agents.

Tony smiled and shook his head.

“You’ll understand what I mean in a bit. Cap, do you think you can carry Bruce?”

Steve still looked kind of overwhelmed but he still answered.

“Sure, but why would I…”

“Great, you do that then. Birdbrain, you go find our weapons and my armor. Tasha, you help me kill the guards. Thor… help Cap with Bruce and maybe kick some ass too, ok?”

Everyone nodded, but Clint intervened again.

“That’s great and all, but how are you planning on doing all that when we are stuck in this cell?”

Tony didn’t answer. Instead, he turned back towards the bars.

Sparing one last glance towards his team, he repeated

“Don’t freak out, ok?”

Closing his eyes, he took a deep breath and felt the fire burn inside him. Giving into it, he heard someone curse as the transformation started.

When he opened his eyes again, his senses were a lot clearer. He could smell his teammates’ fear and hear their hearts picking up speed. He ignored them for the time being, turning his attention back to the bars in front of him.

He placed his hands towards them, concentrating the fire inside his palms. When he thought it was strong enough, he let it out. Flames enveloped the metal, which melted in less than ten seconds.

Cutting off the fire, he stepped out of the now open cage.

When he turned back, the Avengers were staring at him in shock. He knew how scary he looked as a demon, and while he certainly was fascinating, it was also quite unsettling if you weren’t used to it.

He raised an eyebrow.

“So? Are we going or not?”

Steve was the first one to break out of his stupor. With a grunt, he adjusted his grip on Bruce so that he rested on his shoulder.

“When we arrive at the Tower, we’re going to have a long discussion, Iron Man.”

Tony smiled.

“Aye aye, Captain.”

 

-

 

Things didn’t change that much after all.

He went back to what he used to do with Pepper and Rhodey, and the team didn’t seem to mind.

Bruce had to be informed of the situation when he woke up, and took the whole thing remarkably well.

(He asked Tony to participate in some experiments to find out the extent of his powers. Tony accepted. They almost burned the whole workshop in one memorable occasion. Steve was not amused.)

Clint started to make demon jokes at every possible occasion. He also tried to shoot him for “science” multiple times.

(Tony bought a t-shirt with “I’m hot as hell” plastered on it. Clint almost died of laughter when he saw it. He now has a matching one.)

Natasha stopped holding back during their training sessions, which left him with quite a few bruises, and she asked him if he knew others demons she could meet.

(Tony decided that she was scary and that _for no reason_ she was to ever meet his father. She would have made an amazing queen in Hell.)

Thor didn’t really change much. He just patted Tony in the back and exclaimed something about “Another Shield-brother who does not belong to Midgard!” and about celebrating the occasion.

(During the party Tony discovered that Asgardian booze could make him drunk even in his demon form. Clint was delighted. Cap almost had a heart attack.)

And Steve, well, he looked like a kicked puppy when Tony told him about Howard, but afterwards he just kept acting like normal.

(He cooked spicy foods for Tony when he found out that he loved them. Tony kept acting like they were too hot and then spitting out a bit of fire and smoke. The first time he did it the entire team laughed so hard that they ended up on the floor. Steve actually cried.)

Pepper and Rhodey joined them too sometimes, and that were the best times.

Because for the first time in his life, Tony had a real family, and he loved it.

 

**Author's Note:**

> This was just something I had in mind but I didn't have much time to explore it. I think I might write more on this if people like it, so let me know what you think!
> 
> The italian at the beginning just means "My child" and "Okay, mom."
> 
> English is not my first language so if you find any grammar errors or mistakes in general please let me now.  
> P.S: I don't have a beta reader right now, but I'm looking for one so if you are interested hit me up!
> 
> you can also find me on tumblr [here](http://lunaticalwriter.tumblr.com/)
> 
> Kudos and comments are appreciated!


End file.
